Conservative senator and ally of President Michel Temer, Aecio Neves, was caught on tape asking for hefty bribes.

Brazil's top court approved Thursday an investigation into unelected President Michel Temer over a new explosive wiretap recording that revealed the president had signed off on sizeable bribes to manage the fallout of corruption scandals swirling around his administration and keep a powerful witness from speaking out on government corruption, Brazil's Globo TV reported.

The decision came hours after the Federal Supreme Court suspended Senator Aecio Neves Thursday morning, a Temer ally who was also embroiled in the wiretap scandal for soliciting hefty bribes. Police carried out search warrants in apartments owned by Neves in Rio de Janeiro and Belo Horizonte, as well as his and other lawmakers’ congressional offices as part of the country’s largest-ever corruption probe, known as Operation Car Wash, investigating dozens of politicians and business elites involved in fraud schemes linked to the state-run oil company, Petrobras.

The court's decisions came a day after one of Brazil’s largest newspapers, O Globo, released damning wiretap evidence that the senator had requested bribes to the tune of 2 million Brazilian reais, or about US$638,000 from Joesley Batista, an owner of the world’s largest meat processing company, JBS. Authorities arrested Thursday the senator's sister Andrea Neves and cousin Frederico Pacheco de Madeiros, who reportedly received suitcases of dirty money from Batista on Neves' behalf.

Neves had previously been named in the high-profile Operation Car Wash investigations together with Temer and a number of his top allies. In 2014, the senator lost the presidential runoff election to Rousseff and was a leading advocate of the ill-footed impeachment campaign against her, widely condemned as a coup.

The court also ordered the suspension of lower house lawmaker Rodrigo Rocha Loures, a member of Temer's conservative PMDB party and former top aide to the president. The Batista wiretap also implicated Rocha for receiving bribes to sort out issues with a JBS holding, J&F.

The same tape revealed that Temer had also given his blessing to hefty bribes in the name of keeping a key witness, Eduardo Cunha, quiet in the corruption investigations. Cunha, the former speaker of the lower house, the chief mastermind behind the parliamentary coup dressed as an impeachment process against former President Dilma Rousseff and an ally of the unelected president, was sentenced to 15 years in jail in March for corruption, money laundering and tax evasion.

Many analysts expected Cunha — who despite wielding significant political power has been seen as one of the most unpopular politicians in the country — to bring down other corrupt politicians with him by negotiating a plea bargain to reduce his sentence in exchange for evidence to advance the Car Wash investigations. Following Cunha's suspension as speaker of the lower house last year, Brasil de Fato columnist Tico Santa Cruz called the politician a potential "suicide bomber" who could make "heads roll" and the government "implode" if he testified in corruption cases.

Batista recorded the March 7 meeting with Temer and other politicians as part of an attempt to secure a plea bargain deal with prosecutors. O Globo reported the contents of the wiretap Wednesday night, without disclosing how the newspaper gained access to the recording. The Supreme Court approved the plea bargain for Joesley and his brother Wesley Batista on Thursday after the release of the content of the tape.

Temer denied Thursday the accusations that he endorsed paying off Cunha to keep him quiet in prison and dismissed calls for him to step down over the latest scandal rocking his government. The president also cleared his schedule for the rest of the day to manage the fallout from the wiretap release and was expected to make a public address on national TV within hours, according to his aides.

Temer's administration has been embroiled in corruption scandals since being installed in power last year, but the Batista tape is perhaps the strongest blow to the stability of the unelected government yet, plunging the already highly unpopular executive deeper into crisis. The news sparked calls for Temer's impeachment, halted debate on controversial neoliberal reforms and raised serious questions about the ability of the government to survive until the 2018 presidential election.

The president already faces the possibility of being unseated through a trial set to restart next month in the country's top electoral court. The case probes alleged illegal campaign funding in Rousseff's successful bid for re-election in 2014 with Temer as her running mate and could ultimately annul the election results, booting Temer from office early.

The case could take as long as one year, and Temer's defense is expected to employ stall tactics to avoid the court reaching a decision before his term ends in 2018.